1. Field of the Invention
The present invention relates to disposing of hazardous waste underground. The method and system of the present invention could also be utilized for disposing of other hazardous waste such as chemical warfare waste, biomedical waste, or the like. More particularly, the present invention relates to a system and a method for safely disposing spent nuclear wastes at various depths underground through the use of a horizontal borehole or a plurality of radial boreholes drilled off of a horizontal borehole, utilizing a two drillstring technique, with the nuclear wastes sealed therein at a safe distance below the surface of the earth beyond any water sands or permeable formations.
2. General Background of the Invention
One of the more prevalent problems that is being addressed in the twentieth century and will need to be continued addressed even on a larger scale in the twenty first century, is the problem of nuclear wastes, such as spent nuclear waste from nuclear plants and the like. At the present time, the single manner in which the threat of nuclear wastes is addressed is through storage of the wastes. To now, there has been no attempt to safely dispose of nuclear wastes.
The most serious problem is the type of spent nuclear wastes which are generated as a waste product from the operation of nuclear facilities, more particularly, nuclear plants which generate electrical power. Such nuclear plants are located throughout the world, and every nation in which the plants are located must eventually address the problem of safely disposing the waste product from these plants in such a manner that is not harmful to the surrounding environment either at the present or for future generations. Storage of wastes will become prohibitively expensive and difficult to continue.
One method that has evolved in the storing of nuclear wastes is placing the nuclear wastes in containers, such as sealed drums, and storing the drums within salt caverns below the surface of the earth. This is a quite popular means of storing nuclear wastes in view of the fact that salt (NaCl) has a "self-sealing" trait, so that if there is a potential leak, and a container housing the wastes is surrounded by salt, then the salt would tend to form a natural seal at the leak and help prevent further leakage. However, one of the problems that occur in the storage of nuclear wastes within salt caverns is that the caverns are normally located at quite shallow depths, sometimes between one to three thousand feet and are usually approximately 100-200 feet in thickness. If there is inadvertent leakage at this shallow depth, there is a potential of contaminating the water table in that region. This method, again, is addressing storage of the nuclear wastes, not disposal of the wastes, and would require constant monitoring, and construction of expensive facilities to house the nuclear wastes.
There have been alternative methods which have been attempted for storage of nuclear wastes further beneath the earth's surface. Such methods include the construction of storage facilities far beneath the surface of the earth, for example through a series of underground mines which may store tons of radioactive nuclear waste. However, one can well imagine that when such a storage facility is constructed, the billions of dollars of expense that is incurred in the construction of such underground waste storage facilities. Most of these facilities are constructed so that the underground tunnels are able to accommodate even vehicles such as trucks for transporting the nuclear wastes thousands of feet under the ground and the storage mines are of sufficient size so as to allow these vehicles to traverse through the mines for the placement of the waste and storage. Of course, these mines must be carefully constructed and supported so that should there be an inadvertent leak of the waste in these mines, that the mines are self-contained and leakage into the surrounding environment of the radioactive wastes is avoided.
Even in the event such underground mines are constructed at the enormous costs, further enormous costs are incurred in the continued maintenance and monitoring of the underground mines during the time period that the nuclear wastes are stored. This would normally require a substantial amount of manpower and hardware in order to monitor the status of the waste, not to mention the cost of maintaining the facility itself in order to maintain it in its completely upgraded state.
However, because of the nature of the wastes, most of the methods for dealing with nuclear wastes generated by a plant or the like, result in the wastes being stored on site, and are never really disposed of. The problem of disposal has not yet been properly solved. Therefore, there is a need in the art for a process or a system for not only storing nuclear wastes, but of finally disposing of the wastes, which would provide a vast, yet safe disposal area that could receive the wastes, and would require no continuous monitoring or maintenance.
Another serious problem which needs to be addressed is the disposal of waste which are stockpiling in the environment as a result of weapons filled with deadly chemicals which may have been designed for use in warfare, and which because of their deadly nature, cannot be stored for any great length of time and must be properly disposed of. Additionally, other waste in the environment such as biological waste which again cannot be simply stored in a safe manner should be disposed of within a setting which guarantees its complete isolation from the environment.